The Kentucky River is a tributary of the Ohio River, 260 miles (418 km) long,[1] in the U.S. state of Kentucky. The river and its tributaries drain much of the central region of the state, with its upper course passing through the coal-mining regions of the Cumberland Mountains, and its lower course passing through the Bluegrass region in the north central part of the state. Its watershed encompasses about 7,000 square miles (18,000 km2). It supplies drinking water to about one-sixth of the population of the state.

The river is no longer navigable above Lock 4 at Frankfort. Concrete bulkheads have been poured behind the upper lock gates of Locks 5-14 to strengthen the weakest link in the dam structures. All 14 dams are now under the management of the state-run Kentucky River Authority. The primary importance of the locks today is to maintain a pool that allows the city of Lexington to draw its drinking water from the river. Despite the fact that the Lexington area receives well over 40 inches (1,000 mm) of precipitation annually, the limestone, karstgeology of that area means that surprisingly little natural surface water is found in the region.

Approximately 15 miles (24 km) southwest of Boonesborough it is joined by the Red River. Approximately 20 miles (32 km) southwest of Boonesborough it is joined by Silver Creek. At High Bridge, it is joined by the Dix River. At Frankfort, it is joined by Benson Creek. Approximately 10 miles (16 km) north of Frankfort, it is joined by Elkhorn Creek.

The North Fork Kentucky River is approximately 168 miles (270 km) long.[1] It rises on the western side of Pine Mountain, in the Appalachians of extreme southeastern Kentucky, in eastern Letcher County near the Virginia state line in Payne Gap, near the intersection of US 23 and US 119. It flows generally northwest, in a winding course through the mountainous Cumberland Plateau, past Whitesburg, Hazard and Jackson. It receives Rockhouse Creek at Blackey near its source. Approximately 8 miles (13 km) southeast of Hazard, it receives the Carr Fork. It receives Troublesome Creek at Haddix, southeast of Jackson. Three miles upstream from its confluence with the South Fork, it receives the Middle Fork. It joins the South Fork to form the Kentucky at Beattyville.

The Middle Fork Kentucky River is a tributary of the North Fork Kentucky River, approximately 105 miles (169 km) long,[1] in southeastern Kentucky. It rises in the Appalachian Mountains in southernmost Leslie County, approximately 16 miles (26 km) from the Virginia state line, and flows north through the Cumberland Plateau past Hyden. At Buckhorn, it is impounded to form the Buckhorn Lake reservoir. North of the reservoir it flows generally northwest and joins the North Fork in Lee County, approximately 5 miles (8 km) east of the confluence of the North and South forks at Beattyville.